Made it! Crowds pack the 74th St. Broadway station to catch a Flushing-bound 7 train, one minute before the noon shutdown. Photo: riyad hasan

The edge of the hurricane reached New York City late Saturday night, Mayor Bloomberg said.

As if a hurricane weren’t enough, the National Weather Service also said conditions are ripe for tornadoes in New York City, Long Island and southern Connecticut because of the impending storm.

The agency issued a tornado watch effective until 5 a.m. Sunday, meaning only that conditions are favorable to tornadoes and not that any have been spotted.

A twister — common during hurricanes — did touch down near Lewis, Delaware, but there were no reports of injuries.

The announcement comes as frenzied New Yorkers emptied grocery stores, grabbed at every last flashlight and evacuated their homes, and the MTA shut down its entire transit system in anticipation of Irene walloping the city.

The Port Authority announced late this evening that the lower levels of the George Washington Bridge will be shut in both directions, although the upper levels remain open.

The city also announced early this morning that it is closing three bridges in the Rockaways — Broad Channel, Cross Bay and Marine Parkway — due to high winds.

More than 273,000 homes and businesses in New Jersey are also without power.

Atlantic City Electric says it has about 104,000 customers out, including about 37,000 in Atlantic County, as of 12:30 a.m. Sunday.

Public Service Electric and Gas is reporting nearly 89,000 customers without power.

Jersey Central Power and Light has about 80,000 customers out, mostly in Monmouth and Ocean counties.

Atlantic City Electric said it is considering cutting off power to barrier islands in southern New Jersey if there is extensive flooding.

ACE Region President Vince Maione said the shutdown would be done to limit damage to equipment. He noted the areas under consideration are under mandatory evacuations so the immediate impact on customers would be minimal.

Howling winds will pick up tonight, and Irene will crash into the city at 8 a.m. tomorrow. Forecasters predict she’ll unleash the most fury three hours later when her eye passes over an area east of the five boroughs.

City officials cautioned that if Irene stayed on track, it could bring gusts overnight that could shatter skyscraper windows.

“The storm is headed in this direction – slightly east, slightly west, slightly stronger, slightly weaker – but this is a storm where if you’re in the wrong place at the wrong time, it can be fatal,” Mayor Bloomberg warned.

“The time for evacuation is over. Everyone should now go inside and stay inside,” he said late Saturday night.

By late Saturday night, the storm had sustained winds of 80 mph, down from 100 mph on Friday. That made it a Category 1, the least threatening on a 1-to-5 scale, and barely stronger than a tropical storm.

Nevertheless, it was still considered highly dangerous, capable of causing ruinous flooding across much of the East Coast with a combination of storm surge, high tides and 6 to 12 inches of rain.

Irene was moving north-northeast at 16 mph, slightly faster than it had been earlier in the day, giving it somewhat less opportunity to dump on any particular area. But a typical hurricane would be moving much faster, 25 to 30 mph, said senior hurricane specialist Stacy Stewart of the National Hurricane Center.

Moving slowly over the relatively colder water could weaken the storm, but Stewart said Irene will still likely be a hurricane when it makes landfall in the New York area around noon Sunday.

Ed Rappaport, deputy director of the National Hurricane Center in Florida, said it would be a “low-end hurricane, high-end tropical storm” by the time it crossed the New York City area late Sunday morning.

The storm is so large that areas far from Irene’s center are going to be feeling strong winds and getting large amounts of rain, he said.

“It is a big, windy, rainy event,” he said.

Transit workers began the arduous system halt — the first weather-related one in history — at noon. Bus and subway service might not get moving until well into Monday afternoon. The apocalyptic standstill leaves five million riders without a way around.

Minutes into the shutdown, passengers rushed to snag seats on the last rides out of town and many unlucky commuters were left stranded. At the start of the day MTA workers shielded glass booths with plywood and aired booming warnings that the clock was ticking.

By afternoon, underground stations were cordoned off in colorful tape.

Late Saturday night, New York City transit officials said they finished an unprecedented shutdown of the nation’s biggest system of subways, buses and commuter rails ahead of Hurricane Irene.

The Metropolitan Transportation Authority said Saturday night it had secured all its equipment and sent employees home.

Mayor Bloomberg recommended hitchhiking or sharing a cab to escape the storm’s wrath. “You could hail a cop car,” he said.

The city began transporting public housing residents living in “Zone A” areas to shelters since NYCHA stopped elevator service. Approximately 8,700 people are in shelters throughout the city.

Some hotels were shutting off their elevators and air conditioners. Others had generators ready to go.

Since this morning, police spread to stubborn residents to hightail it out of areas deemed dangerous.

“They will be doing that all afternoon into the evening, but keep in mind, if you want to evacuate later on, you’re going to be on your own,” Bloomberg said at a Coney Island presser this morning.

Meanwhile, Con Edison is considered zapping power to lower Manhattan starting sometime tomorrow between 2 a.m. and 10 a.m. Sunday – leaving lights out for three days.

Con Ed feared that flooding salt water would ruin and short out two underground networks.

“If salt water gets on these cables when they are being used the damage is substantial,” Mayor Bloomberg said.

While the foot of Manhattan is protected by a seawall and a network of pumps, Con Ed vice president John Mucci said the utility stood ready to turn off the power to about 17,000 people in the event of severe flooding.

Mucci said it could take up to three days to restore the power if the cables became drenched with saltwater, which can be particularly damaging.

The New York Stock Exchange has backup generators and can run on its own, a spokesman said.

Con Ed also shut down about 10 miles of steam pipes underneath the city to prevent explosions if they came in contact with cold water. The shutdown affected 50 commercial and residential customers around the city who use the pipes for heat, hot water and air conditioning.

Water surges could climb eight feet above high tide at 8 a.m., licking the southern-most tip of Manhattan.

“If those stars align we could be dealing with the issue of preemptively shutting down those networks in order to prevent widespread damage because salt water and electricity do not mix well,” said John Miksad, Con Ed’s senior vice president of electrical operations.

Four hundred crews came in from as far away as Colorado to lend Con Ed a hand. The voluntary power zap would stretch on for days affecting 6,500 customers, leaving thousands of apartments and offices without juice.

In Battery Park City, the massive emptying began under chalky white skies, leaving the downtown district eerily silent.

Evacuation areas also include Far Rockaway and Broad Channel in Queens, Coney Island in Brooklyn and sections of City Island and Throggs Neck in The Bronx and parts of Staten Island.

City police rescued two kayakers who capsized in the surf off Staten Island. They were found with their life jackets on, bobbing in the roiling water.

Wind gusts could reach velocities up to 85 mph. Although the hurricane was downgraded from a Category 2 to 1, the mayor discouraged people from taking the beastly storm less seriously.

He said that clearing out immediately meant that emergency crews didn’t waste time fishing people out of their homes. Then he displayed ominous pictures of boats.

“You’ve probably seen boats like this before,” he said. “There’s lots of news footage after Hurricane Katrina that was certainly full of images of these boats, and the emergency responders that rowed through the flooded streets, rescuing stranded residents.”

The hurricane stirred up seven-foot waves, and forecasters warned of storm-surge danger on the coasts of Virginia and Delaware, along the Jersey Shore and in New York Harbor and Long Island Sound.